Which of the following most logically completes the passage?
Garnet and RenCo each provide health care for their employees. Garnet pays for both testing of its employees’ cholesterol levels and treatment of high cholesterol. This policy saves Garnet money, since high cholesterol left untreated for many years leads to conditions that require very expensive treatment. However, RenCo dose not have the same financial incentive to adopt such a policy, because ______.
A. early treatment of high cholesterol dose not entirely eliminate the possibility of a stroke later in life
B. the mass media regularly feature stories encouraging people to maintain diets that are low in cholesterol
C. RenCo has significantly more employees than Garnet has
D. RenCo’s employees are unlikely to have higher cholesterol levels than Garnet’s employees
E. the average length of time an employee stays with RenCo is less than it is with Garnet
请问答案为什么是E？我想不透。 | 
